Flashers
The rhythm is the name — every light blinks its own signature.
Rhythm is the name
A flasher is a light that blinks, and the blink is its name. The exact on-off timing tells you which light you're looking at, from miles away, in the dark.
The grammar
Fl 2s one flash, every 2 seconds Fl(3) 15s three flashes, then dark Q 1s quick — near-buzzing fast LFl 10s one long flash
Why they matter
Count the flashes and time the gap, and you know exactly which light it is — no chart needed, even in the dark.